In recent years, a liquid crystal display (LCD: Liquid Crystal Display) is often used as a display monitor for a liquid crystal television, a notebook personal computer, a car navigation system and the like. The liquid crystal display is categorized into various display modes (methods) according to molecular arrangement (alignment) of liquid crystal molecules contained in a liquid crystal layer sandwiched by substrates. As a display mode, TN (Twisted Nematic) mode in which twisted liquid crystal molecules are aligned in a state that a voltage is not applied is well-known. In the TN mode, the liquid crystal molecules have positive dielectric constant anisotropy, that is, characteristics that the dielectric constant in the long axis direction of the liquid crystal molecules is larger than that in the short axis direction of the liquid crystal molecules. Thus, the liquid crystal molecules are arrayed in a direction vertical to a substrate face while the alignment direction of the liquid crystal molecules is sequentially rotated in a plane in parallel with the substrate face.
Meanwhile, attention is drawn to VA (Vertical Alignment) mode in which liquid crystal molecules are aligned vertical to a substrate face in a state that a voltage is not applied. In the VA mode, the liquid crystal molecules have negative dielectric constant anisotropy, that is, characteristics that the dielectric constant in the long axis direction of the liquid crystal molecules is smaller than that in the short axis direction of the liquid crystal molecules, and a wider view angle is able to be realized than TN mode.
In such a VA mode liquid crystal display, in the case where a voltage is applied, response is made so that the liquid crystal molecules aligned in the direction vertical to the substrate fall over in the direction in parallel with the substrate due to negative dielectric constant anisotropy, and thereby light is transmitted. However, the direction in which the liquid crystal molecules aligned in the direction vertical to the substrate fall is arbitrary. Thus, in the case where a voltage is applied, the alignment of the liquid crystal molecules is disarrayed, which causes deteriorated response characteristics to the voltage.
To improve the response characteristics, technologies to regulate the direction in which the liquid crystal molecules fall responsive to a voltage have been studied. Specific examples include a technology in which pretilt is given to the liquid crystal molecules by using an alignment film formed by radiating linear polarized light of ultraviolet or ultraviolet light from a direction diagonal to the substrate face (photo alignment film technology) and the like. As the photo alignment film technology, a technology in which an alignment film is formed by radiating linear polarized light of ultraviolet or ultraviolet light from a direction diagonal to the substrate face to a film including a polymer containing chalcone structure, and bridging a double bond section in the chalcone structure is known (refer to Patent literature 1 to Patent literature 3). Further, in addition, there is a technology in which an alignment film is formed by using a mixture of a vinylcinnamate derivative polymer and polyimide (refer to Patent literature 4). Further, a technology in which an alignment film is formed by radiating linear polarized light with a wavelength of 254 nm to a film containing polyimide and decomposing part of the polyimide (refer to Patent literature 5) and the like are known. Further, as a peripheral technology of the photo alignment film technology, there is a technology in which a liquid crystalline alignment film is formed by forming a film including a liquid crystalline polymer compound on a film including a polymer containing a dichroic photoreactive constituent unit such as an azobenzen derivative irradiated with linear polarized light or diagonal light (refer to Patent literature 6).